It is well known in the hydraulic equipment industry to have a hose connector for securing a high pressure hose with, a high pressure port. Normally, hydraulic hoses meeting a certain industry pressure standard use connectors, such as a split flange connector, to join the hose to a high pressure port meeting the same industry standard. For example, a 6,000 psi hydraulic hose is joined to a 6,000 psi hydraulic port with both the hose flanged head and the hydraulic port being designed and dimensioned to meet the specific dimensions as set by the industry SAE Code 62 standard for 6,000 psi hydraulic hoses and ports. The split flange connector halves, such as taught by the U.S. Pat. No. 2,681,817 issued June 22, 1954, to Demlow, would have a bolt pattern and internal dimensions also meeting the industry SAE Code 62 standard for split flange clamp halves. SAE standard J518c, last revised in May, 1972 provides diagrams and appropriate dimensions for the hose flanged head, hydraulic port, and the split flange clamp halves.
In the hydraulic industry it is not unusual to encounter the intentional use of hydraulic hoses meeting one industry specification to connect hydraulic ports meeting a different industry specification. A prime example is the use of 5,000 psi rated hydraulic hoses (SAE Code (61) in certain lower pressure applications to form the closed loop of a hydrostatic transmission by connecting hydraulic units having ports designed to meet the industry 6,000 psi standard rating (SAE Code 62). The hydraulic unit manufacturer, for obvious reasons, designs the hydraulic unit ports so that the hydraulic unit can effectively be used in a system at the maximum pressure rating of the unit. However, the hydraulic unit is often used in applications not requiring such high pressures and the end user incorporates lower pressure rated hoses to interconnect the higher pressure designed hydraulic pump and motor units, especially when they are spaced at any significant difference. The end user selects such lower pressure rated hoses for both cost savings and inherent flexibility when compared to hydraulic hoses at various pressure ratings. While various pressure rated hoses are available, it is not industry practice to build hydraulic units at lower pressure ratings, or at higher pressure ratings with lower pressure rating ports, due to the extra tooling required and other complications such as multiple inventory.
It has therefore become industry practice to design the housing port sizes for the maximum pressure rating of the unit and to use an adaptor plate which receives a standard split flange connector and hydraulic hose flanged head dimensioned to a first industry standard and with the adaptor also having a second bolt pattern designed to fit a different industry standard hydraulic port specification. Thus an adaptor is designed to receive a 5,000 psi rated SAE Code 61 hose and split flange connector and at the same time patterned to connect to a 6,000 psi rated SAE Code 62 port. Unfortunately, such adaptors in themselves, while quite simple, are relatively expensive with prices ranging up to $50.00 as an after-market service part.
There have been hose clamps designed such as taught in U.S. Pat. No. 4,426,103, issued Jan. 17, 1984, to Sundholm, wherein specialized eccentric flange pieces are used and which are adaptable to receive more than one size of hose flanged head for connection of a low pressure hose to a hydraulic port. While such clamps provide some adaptability, this leads to certain compromises such as not surrounding the hose flanged head and thus does not lend itself to high pressure application.